1 /* ----------------------------------------------------------------------- * 2 * 3 * Copyright 2002-2009 H. Peter Anvin - All Rights Reserved 4 * Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin 5 * 6 * Permission is hereby granted, free of charge, to any person 7 * obtaining a copy of this software and associated documentation 8 * files (the "Software"), to deal in the Software without 9 * restriction, including without limitation the rights to use, 10 * copy, modify, merge, publish, distribute, sublicense, and/or 11 * sell copies of the Software, and to permit persons to whom 12 * the Software is furnished to do so, subject to the following 13 * conditions: 14 * 15 * The above copyright notice and this permission notice shall 16 * be included in all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 20 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 22 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 24 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 25 * OTHER DEALINGS IN THE SOFTWARE. 26 * 27 * ----------------------------------------------------------------------- */ 28 29 /* 30 * com32.h 31 * 32 * Common declarations for com32 programs. 33 */ 34 35 #ifndef _COM32_H 36 #define _COM32_H 37 38 #include <stdint.h> 39 #include <stdbool.h> 40 #include <stddef.h> 41 #include <klibc/compiler.h> /* For __cdecl */ 42 43 /* 44 * This structure defines the register frame used by the 45 * system call interface. 46 * 47 * The syscall interface is: 48 * 49 * __intcall(interrupt_#, source_regs, return_regs) 50 * __farcall(seg, offs, source_regs, return_regs) 51 */ 52 typedef union { 53 uint32_t l; 54 uint16_t w[2]; 55 uint8_t b[4]; 56 } reg32_t; 57 58 typedef struct { 59 uint16_t gs; /* Offset 0 */ 60 uint16_t fs; /* Offset 2 */ 61 uint16_t es; /* Offset 4 */ 62 uint16_t ds; /* Offset 6 */ 63 64 reg32_t edi; /* Offset 8 */ 65 reg32_t esi; /* Offset 12 */ 66 reg32_t ebp; /* Offset 16 */ 67 reg32_t _unused_esp; /* Offset 20 */ 68 reg32_t ebx; /* Offset 24 */ 69 reg32_t edx; /* Offset 28 */ 70 reg32_t ecx; /* Offset 32 */ 71 reg32_t eax; /* Offset 36 */ 72 73 reg32_t eflags; /* Offset 40 */ 74 } com32sys_t; 75 76 /* EFLAGS definitions */ 77 #define EFLAGS_CF 0x00000001 78 #define EFLAGS_PF 0x00000004 79 #define EFLAGS_AF 0x00000010 80 #define EFLAGS_ZF 0x00000040 81 #define EFLAGS_SF 0x00000080 82 #define EFLAGS_TF 0x00000100 83 #define EFLAGS_IF 0x00000200 84 #define EFLAGS_DF 0x00000400 85 #define EFLAGS_OF 0x00000800 86 #define EFLAGS_IOPL 0x00003000 87 #define EFLAGS_NT 0x00004000 88 #define EFLAGS_RF 0x00010000 89 #define EFLAGS_VM 0x00020000 90 #define EFLAGS_AC 0x00040000 91 #define EFLAGS_VIF 0x00080000 92 #define EFLAGS_VIP 0x00100000 93 #define EFLAGS_ID 0x00200000 94 95 struct com32_pmapi; 96 97 extern struct com32_sys_args { 98 uint32_t cs_sysargs; 99 char *cs_cmdline; 100 void __cdecl (*cs_intcall)(uint8_t, const com32sys_t *, com32sys_t *); 101 void *cs_bounce; 102 uint32_t cs_bounce_size; 103 void __cdecl (*cs_farcall)(uint32_t, const com32sys_t *, com32sys_t *); 104 int __cdecl (*cs_cfarcall)(uint32_t, const void *, uint32_t); 105 uint32_t cs_memsize; 106 const char *cs_name; 107 const struct com32_pmapi *cs_pm; 108 } __com32; 109 110 /* 111 * System call wrapper functions 112 */ 113 void __intcall(uint8_t __i, const com32sys_t * __sr, com32sys_t * __dr); 114 void __farcall(uint16_t __cs, uint16_t __ip, 115 const com32sys_t * __sr, com32sys_t * __dr); 116 int __cfarcall(uint16_t __cs, uint16_t __ip, 117 const void *__stack, uint32_t __stack_size); 118 extern const com32sys_t __com32_zero_regs; 119 120 /* 121 * Lowmem allocation functions 122 */ 123 void *lmalloc(size_t); 124 void *lzalloc(size_t); 125 void lfree(void *); 126 char *lstrdup(const char *); 127 128 /* 129 * These functions convert between linear pointers in the range 130 * 0..0xFFFFF and real-mode style SEG:OFFS pointers. Note that a 131 * 32-bit linear pointer is not compatible with a SEG:OFFS pointer 132 * stored in two consecutive 16-bit words. 133 * 134 * Use OFFS_WRT() if you want to compute an offset relative to a 135 * specific segment. OFFS_VALID() will return whether or not the 136 * pointer is actually reachable from the target segment. 137 */ 138 #if defined(CORE_DEBUG) && (defined(__COM32__) || defined(__SYSLINUX_CORE__)) 139 __noreturn __bad_SEG(const volatile void *); 140 141 static inline uint16_t SEG(const volatile void *__p) 142 { 143 if (__unlikely((uintptr_t)__p > 0xfffff)) 144 __bad_SEG(__p); 145 146 return (uint16_t) (((uintptr_t) __p) >> 4); 147 } 148 #else 149 static inline uint16_t SEG(const volatile void *__p) 150 { 151 return (uint16_t) (((uintptr_t) __p) >> 4); 152 } 153 #endif 154 155 static inline uint16_t OFFS(const volatile void *__p) 156 { 157 /* The double cast here is to shut up gcc */ 158 return (uint16_t) (uintptr_t) __p & 0x000F; 159 } 160 161 static inline uint16_t OFFS_WRT(const volatile void *__p, uint16_t __seg) 162 { 163 return (uint16_t) ((uintptr_t) __p - ((uintptr_t) __seg << 4)); 164 } 165 166 #define OFFS_VALID(p,s) _OFFS_VALID((p), sizeof *(p), (s)) 167 168 static inline bool _OFFS_VALID(const volatile void *__p, size_t __s, 169 uint16_t __seg) 170 { 171 uintptr_t __segstart = (uintptr_t)__seg << 4; 172 uintptr_t __offs = (uintptr_t)__p - __segstart; 173 174 return __offs <= 0x10000-__s; 175 } 176 177 static inline void *MK_PTR(uint16_t __seg, uint16_t __offs) 178 { 179 return (void *)(unsigned long)((__seg << 4) + __offs); 180 } 181 182 /* Some tools to handle 16:16 far pointers in memory */ 183 184 struct __far_ptr { 185 union { 186 uint32_t ptr; 187 struct { 188 uint16_t offs, seg; 189 }; 190 }; 191 } __attribute__ ((packed)); 192 193 typedef struct __far_ptr far_ptr_t; 194 195 static inline void *GET_PTR(far_ptr_t __fptr) 196 { 197 return MK_PTR(__fptr.seg, __fptr.offs); 198 } 199 200 static inline far_ptr_t FAR_PTR(void *__ptr) 201 { 202 far_ptr_t __fptr; 203 204 __fptr.offs = OFFS(__ptr); 205 __fptr.seg = SEG(__ptr); 206 return __fptr; 207 } 208 209 extern const char *com32_cmdline(void); 210 211 #endif /* _COM32_H */ 212
